Forensic and phylogenetic analyses of populations in the Tibetan-Yi corridor using 41 Y-STRs.

Y-chromosome haplotypes of 527 non-related males (176 Han, 186 Tibetan, and 165 Yi) in the Tibetan-Yi corridor were analyzed using SureID® PathFinder Plus. In the populations of Han, Tibetans, and Yi, the haplotype diversity was 0.9989, 0.9981, and 0.9993, respectively, and the discrimination capacity was 0.9148, 0.8925, and 0.9576, respectively. Phylogenetic relationships among 12 studied ethnic groups and 7 other ethnic groups in the Tibetan-Yi corridor were investigated. Both multi-dimensional scaling analysis and phylogenetic reconstructions indicated that Tibetans appeared separated from the Han and Yi ethnic groups in the Tibetan-Yi corridor. Their genetic homogeneity or heterogeneity has not entirely been affected by their geographical distance and linguistic origin.

Gene flow and phylogenetic analyses of paternal lineages in the Yi-Luo valley using Y-STR genetic markers.

BACKGROUND: The Yi-Luo valley witnessed the most significant socio-political transformation of China and was deeply implicated in several enormous migrations of the Han population. However, little has been done to clarify its paternal genetic variation or phylogenetic relationship, particularly concerning the genetic evidence of their migrations. AIM: This study aims to uncover the population genetic characteristics in the Yi-Luo valley and provide genetic evidence for its people's migrations. SUBJECTS AND METHODS: Seventeen Y-STR loci included in the AmpFlSTR®Yfiler™ were typed in 2,314 individuals from seven different regions along the Yi-Luo valley. A multidimensional scaling plot and neighbor-joining tree were constructed for nationwide genetic comparisons. Y-haplogroup frequencies and migration rates were estimated among the studied populations. Gene flows were detected by different migration models and directions. RESULTS: The predicted Y-haplogroups demonstrated the predominance of O2a2. Genetic affinities were observed among Han, Hakka, Danmin, and Bai. Anhui was shown to be the most crucial transfer spot for the Hakkas when they moved out of the Central Plains to South China. CONCLUSIONS: This study reveals the genetic landscape of paternal lineages living in the Yi-Luo valley and enriches our understanding of the great migration in Chinese history.

Developmental validation study of a 32-plex STR direct amplification system for forensic reference samples.

The STRtyper-32G PCR Amplification Kit is a 6-dye multiplex system that combines the 30 autosomal STR loci with an Indel site (YIndel) and the sex-determinant locus Amelogenin. In addition to more loci, Master Mix has been optimized to amplify DNA on different substrates. The autosomal STR loci contained in this novel system meet the compatibility of requirements for databasing. In this study, the developmental validation study of the STRtyper-32G Kit followed the guidelines of SWGDAM (Scientific Working Group on DNA Analysis Methods), including PCR-based studies, species specificity, inhibitors, sensitivity, precision, repeatability, stutter, DNA mixtures, concordance studies, and population genetics studies. The validation results indicate that the new multiplex system is a robust tool for forensic database applications.